double *y; // 数组指针

void init2()
{
    y = (double *)malloc(3 * sizeof(double));
    y[0] = 4;
    y[1] = 5;
    y[2] = 6;
}

void prt2()
{
    printf(" 在 C 中打印：%f ", y[0]);
    printf("%f ", y[1]);
    printf("%f\n", y[2]);
}